A recent, interesting article in the New York Times written by two professors - one from Harvard and one from Yale - reviewed a study they published in the British Medical Journal that finds that male-led scientific teams were up to 21 percent more likely than women-led teams to use positive adjectives to describe their research findings. Importantly, they also found that the greater use of positive language by male-led teams was linked to more citations.
In the NYT article, the authors point out that in many realms and fields women have been found to use language that is more tentative than men. I have found this to be true when I conduct mock interviews as well. I note that, generally, women applicants are less willing to showcase their achievements, which I do believe adversely affects their candidacies. I try to counter that in practice with applicants.
Of course, there is an alternate assessment of this issue: The "Lean Out" crowd feels that women should not have to conform to men's patterns. While I strongly agree in theory, I have witnessed the disadvantage of being overly modest in the application process.
This is a good discussion for your next coffee break with a friend!